Cooking & Kitchen

Butter to Oil Conversion Calculator

Butter is about 80% fat and 20% water and milk solids, so you need roughly 80% as much oil to match its fat.

The result tells you how much oil to use instead of the butter in the recipe, so for 100 g of butter you would use 80 g of oil.

Formula

Oil (g) = butter (g) x 0.8.

How it works

Oil makes cakes moister and keeps them soft for longer, but it cannot cream with sugar the way butter does, so cakes may be denser and less airy.

Choose a neutral oil for baking unless the recipe welcomes flavour — olive oil suits savoury bakes and some chocolate cakes.

Worked example

For example, 100 g of butter × 0.8 = 80 g of oil, which is about 5.9 tablespoons, so a recipe calling for 100 g of butter would use 80 g of oil instead.

FAQs

Can I swap oil back to butter?
Yes, in reverse: use about 125 g of butter for every 100 g of oil, since butter contains water as well as fat.

Does the swap change the taste?
Yes. Butter adds a rich flavour that neutral oil lacks, though the texture often improves with oil.

What about melted butter vs soft butter?
This conversion assumes the same weight either way — melted or soft, 100 g of butter is 100 g.

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